摘要

      传统堆肥在消除抗生素残留、抗生素抗性细菌（ARBs）和抗生素抗性基因（ARGs）方面已经显示出一定的效果。值得注意的是，常规好氧堆肥过程中ARGs的反弹和细菌群落的演替仍然是严重的威胁。考虑到可能存在的风险，迫切需要改进和适应性强的技术来有效控制抗生素耐药性。这项研究监测了高温好氧堆肥如何影响 ARG，以及在添加不同浓度磺胺甲恶唑 (SMX) 的牛粪堆肥过程中的细菌多样性。结果表明，在高温好氧堆肥过程中（对照 > SMX25 > SMX50 > SMX100），SMX 的降解增强，并且在堆肥 20 天后不再检测到。高温或高温显着刺激了某些基因的反弹。 35 天后，检测到的基因（sul2、sulA、dfrA7 和 dfrA1）的丰度在对照和添加抗生素的处理中显着降低（p < 0.05），但 sul1 除外。添加三种浓度的 SMX 对细菌多样性产生了显着影响，SMX25 中的微生物结构导致与其他微生物结构的显着差异（p < 0.05）。网络分析揭示了 ARGs 和丰富的属之间更严格的相互作用，表明 ARGs 的宿主可能在低浓度的 SMX 下增加。特别是 g_norank_f__Beggiatoaceae、Ruminiclostridium、Caldicoprobacter、g_norank_o_MBA03、Hydrogenispora 和 Ruminiclostridium_1 属是 sul1 的主要潜在宿主。总之，与常规方法相比，在高温堆肥中可以部分阻止 ARG 的反弹，并且可以更有效地控制抗生素耐药性。

       Traditional composting has already shown a certain effect in eliminating antibiotic residues, antibiotic-resistant bacteria (ARBs), and antibiotic resistance genes (ARGs). It is worth noting that the rebounding of ARGs and the succession of the bacterial community during conventional aerobic composting are still serious threats. Considering the probable risk, improved and adaptable technologies are urgently needed to control antibiotic resistance efficiently. This study monitored how thermophilic aerobic composting affected the ARGs, as well as the bacterial diversity during the composting of cow manure spiked with sulfamethoxazole (SMX) at different concentrations. Results showed that the degradation of SMX was enhanced during thermophilic aerobic composting (control > SMX25 > SMX50 > SMX100) and was no longer detected after 20 days of composting. High temperature or heat significantly stimulated the rebounding of certain genes. After 35 days, the abundance of detected genes (sul2, sulA, dfrA7, and dfrA1) significantly decreased (p < 0.05) in control and antibiotic-spiked treatments, except for sul1. The addition of three concentrations of SMX elicited a sharp effect on bacterial diversity, and microbial structure in SMX25 led to significant differences with others (p < 0.05). The network analysis revealed more rigorous interactions among ARGs and abundant genera, suggesting that the host of ARGs potentially increased at low concentrations of SMX. Especially, genera g_norank_f__Beggiatoaceae, Ruminiclostridium, Caldicoprobacter, g_norank_o_MBA03, Hydrogenispora, and Ruminiclostridium_1 were major potential hosts for sul1. In conclusion, the rebounding of ARGs could be intermitted partially, and more efficient control of antibiotic resistance could be achieved in the thermophilic composting compared to conventional methods.   

https://www.sciencedirect.com/science/article/abs/pii/S0269749121001652